Six Flags Over Mid-America was the third and final Six Flags park built from scratch. After an investment of over $50 million, the
park opened in 1971. The park was built and owned by Penn Central. Since then it has been owned by a number of organizations including
Bally's, Wesray Capital, Time Warner Corp., and Premier Parks. The park's name was changed to Six Flags St. Louis in order to
better indicate its location. In 2013, the park added Boomerang, the Vekoma Boomerang model that operated at Six Flags
Over Texas from 1989 to 2012.

Three coasters have left the park:

Jet Scream was here from 1981 to 1988. It then ran as
Viper at Six Flags AstroWorld until it was demolished in 2005.

One half of the Mine
Train (see pictures below) was moved to Dollywood and operated there from 1989 to 1998 as
Thunder Express. Now the ride is at Magic Springs and Crystal
Falls in Arkansas and opened in May 2002 as Big Bad John.

The Rockin' Roller (see pictures below) ran from 1975 to 2006.
It was scrapped in 2008.